Method and device for detecting and transmitting information

ABSTRACT

Embodiments of the present invention disclose a method and a device for detecting and transmitting information. The method includes: obtaining, by a UE, at least one type of configuration information of an antenna port occupied by a D-PDCCH, which is configured on a base station side; determining, by the UE, a search space of the D-PDCCH; and detecting, by the UE, the D-PDCCH in the search space according to the antenna port configuration information. With the embodiments of the present invention, the UE can detect the D-PDCCH, and therefore data transmission is ensured. Furthermore, a blind detection of a PDCCH by the UE based on time-frequency resources in an existing system is extended to a spatial dimension, that is, an antenna port, thereby increasing the efficiency of resource utilization, so that the D-PDCCH can be detected in the spatial dimension.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/167,537, filed on Jan. 29, 2014, which is a continuation ofInternational Application No. PCT/CN2012/079816, filed on Aug. 8, 2012,which claims priority to Chinese Patent Application No. 201110225994.3,filed on Aug. 8, 2011, all of which are hereby incorporated by referencein their entireties.

TECHNICAL FIELD

The present invention relates to a wireless communication system, and inparticular, to a method and a device for detecting and transmittinginformation.

BACKGROUND

In an existing long term evolution (LTE) system, a subframe is asmallest time unit scheduled by a base station (eNB, Evolved NodeB),each subframe includes two timeslots, and each timeslot includes sevensymbols. For a scheduled UE, a subframe includes a physical downlinkcontrol channel (PDCCH, Physical Downlink Control Channel) of the userequipment (UE, User Equipment), where the PDCCH is borne in first nsymbols of the subframe, and n may be any one of 1, 2, and 3, or any oneof 2, 3, and 4 (in a case where the system bandwidth is 1.4 MHz).

The PDCCH carries a downlink scheduling grant (DL_grant, Downlink_grant)or an uplink scheduling grant (UL_grant, Uplink_grant), whichrespectively carries scheduling information of a physical downlinkshared channel (PDSCH) or a physical uplink shared channel (PUSCH).Depending on different specific data types (for example, multiple inputmultiple output (MIMO) and non-MIMO data), the PDCCH may have differentdownlink control information (DCI, Downlink Control Information)formats. For example, the DCI formats may be 0, 1, 1A, 2, 2A, 2B, and2C. A payload size (referred to as a payload size in a standard text) ofthe PDCCH corresponding to these DCI formats generally varies.

In the existing LTE system, PDCCH demodulation is uniformly based on acell-specific reference signal (CRS, Cell-specific Reference Signal).FIG. 1 is a schematic diagram showing that a PDSCH is scheduled by aPDCCH in a subframe in the prior art. In FIG. 1, a horizontal axisrepresents a time domain, and a vertical axis represents a frequencydomain. In the prior art, PDCCH information does not undergo MIMOprecoding processing, and the UE may obtain information of an antennaport for transmitting PDCCH by detecting a broadcast channel.Specifically, after the UE demodulates and decodes a PDCCH intime-frequency resources of a search space of the PDCCH according to thepayload size of the PDCCH and an aggregation level of a control channelelement (CCE), the UE uses a UE-specific radio network temporaryidentifier (RNTI) to perform descrambling CRC to check and determine thePDCCH of the UE, and performs, according to scheduling information inthe PDCCH, corresponding reception and transmission processing for aPDSCH or PUSCH scheduled by the PDCCH.

In an LTE system of a later release, technologies such as carrieraggregation, multi-user multiple input multiple output (MIMO, MultipleInput Multiple Output), and coordinated multiple points (CoMP,Coordinated Multiple Points) will be introduced. In addition, aheterogeneous network scenario will be widely applied. All these willlead to a capacity limitation on the PDCCH. Therefore, a PDCCH based onchannel information precoding will be introduced. This PDCCH will bedemodulated based on a UE-specific reference signal. In this case, theUE-specific reference signal may be referred to as a dedicated referencesignal (DRS, Dedicated Reference Signal), while the PDCCH demodulatedbased on the DRS is briefed as a D-PDCCH. Through the D-PDCCH, aprecoding gain may be obtained to improve performance.

FIG. 2 is a schematic diagram showing that a PDSCH is scheduled by aD-PDCCH in a subframe in the prior art. D-PDCCH resources are located ina PDSCH region, and the D-PDCCH and the PDSCH scheduled by the D-PDCCHare divided by frequencies.

However, in the prior art, the UE can only detect the PDCCH based on anon-precoding manner and according to the CRS. For the D-PDCCH based onMIMO precoding, the prior art does not provide a detection method. Ifthe D-PDCCH cannot be detected, data transmission is definitelyimpossible. Therefore, how to ensure that the UE detects the D-PDCCH isa pressing issue to be solved.

SUMMARY

Embodiments of the present invention provide a method and a device fordetecting and transmitting information, so that a UE can detect aD-PDCCH.

An embodiment of the present invention provides a method for detectinginformation, including:

obtaining, by a UE, at least one type of configuration information of anantenna port occupied by a D-PDCCH, which is configured on a basestation side;

determining, by the UE, a search space of the D-PDCCH; and

detecting, by the UE, the D-PDCCH in the search space according to theantenna port configuration information.

An embodiment of the present invention further provides a method fortransmitting information, where the method is applicable to a basestation and includes:

configuring, by a base station, at least one type of configurationinformation of an antenna port occupied by a D-PDCCH for a UE;

determining, by the base station, search space information of theD-PDCCH; and

transmitting, by the base station, the D-PDCCH in the search space tothe UE according to the at least one type of configuration informationof an antenna port occupied by the D-PDCCH which is configured for theUE.

An embodiment of the present invention further provides a userequipment, including:

an obtaining unit, adapted to obtain at least one type of configurationinformation of an antenna port occupied by a D-PDCCH, which isconfigured on a base station side;

a determining unit, adapted to determine a search space of the D-PDCCH;and

a detecting unit, adapted to detect the D-PDCCH in the search spaceaccording to the antenna port configuration information.

An embodiment of the present invention further provides a base station,including:

a configuring unit, adapted to configure at least one type ofconfiguration information of an antenna port occupied by a D-PDCCH for aUE;

a search space determining unit, adapted to determine search spaceinformation of the D-PDCCH; and

a transmitting unit, adapted to transmit the D-PDCCH in the search spaceto the UE according to the at least one type of configurationinformation of an antenna port occupied by the D-PDCCH which isconfigured for the UE.

With the method and the device provided by the embodiments of thepresent invention, a UE can detect a D-PDCCH, and therefore data can betransmitted according to the detected D-PDCCH. Furthermore, a blinddetection of a PDCCH by the UE based on time-frequency resources in anexisting system is extended to a spatial dimension, that is, an antennaport, thereby increasing the efficiency of resource utilization, so thatthe D-PDCCH can be detected in the spatial dimension. In this way, aD-PDCCH detection method is provided, the flexibility of scheduling ofthe D-PDCCH in MU-MIMO is improved, and the reception performance of thePDCCH is improved; in addition, it is ensured that the count of blinddetections by the UE is not greater than that in the existing system,that is, the implementation complexity of the UE is not increased.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate the technical solutions in the embodiments of the presentinvention or in the prior art more clearly, the following brieflyintroduces the accompanying drawings required for describing theembodiments or the prior art. Apparently, the accompanying drawings inthe following description show merely some embodiments of the presentinvention, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a schematic diagram showing that a PDSCH is scheduled by aPDCCH in a subframe in the prior art;

FIG. 2 is a schematic diagram showing that a PDSCH is scheduled by aD-PDCCH in a subframe in the prior art;

FIG. 3 is a flowchart of a method for detecting information according toan embodiment of the present invention;

FIG. 4 is a flowchart of another method for detecting informationaccording to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a UE according to anembodiment of the present invention;

FIG. 6 is a schematic structural diagram of a base station according toan embodiment of the present invention; and

FIG. 7 is a schematic structural diagram of another base stationaccording to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely a part rather than all of theembodiments of the present invention. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments of thepresent invention without creative efforts shall fall within theprotection scope of the present invention.

For better describing this application, the following first describes asearch space and the count of searches briefly.

The search space itself is an existing concept in the prior art, and isonly briefly described herein. The search space is a segment ofresources defined according to a control channel element (CCE), wherethe CCE is an element forming a PDCCH. According to the channelcondition, a UE may use four CCE aggregation levels (corresponding todifferent encoding rates) for transmission, that is, 1, 2, 4, and 8.Each UE has a specific search space. A UE-specific search space isdetermined by a UE-specific RNTI, a CCE aggregation level, and asubframe number.

For detecting a PDCCH corresponding to a DCI format, the count of blinddetections to be performed by the UE, that is, the count of searches, ofa candidate PDCCH in the search space corresponding to the four CCEaggregation levels, is 6, 6, 2, and 2 respectively, and the total countis 6+6+2+2=16.

An eNB configures a transmission mode of data channel transmission forthe UE through RRC dedicated signaling. In each transmission mode, theUE needs to blindly detect two DCI formats (possibly three DCI formatsif uplink MIMO is considered), where one (possibly two if uplink MIMO isconsidered) is a DCI format related to the current mode, for example,DCI format 1, 2, 2A, 2C, and 4, and the other is a common DCI format ineach mode, generally DCI format 0 or 1A (the two are respectively aUL_grant and DL_grant with an equal payload size, and are distinguishedby header bits in signaling, and therefore are used as a DCI formatherein). Considering that the UE determines, according to a transmissionmode, two DCI formats to be detected, in combination with the foregoingcount of blind detections required by the UE for detecting each DCIformat, the total count of blind detections in the UE-specific searchspace by the UE is 2*(6+6+2+2)=32.

Embodiment 1

FIG. 3 is a flowchart of a method for detecting information according toan embodiment of the present invention. The procedure is applicable to auser equipment terminal, and may specifically include:

Step 301: A UE obtains at least one type of configuration information ofan antenna port occupied by a D-PDCCH, which is configured on a basestation side.

In a possible embodiment, the antenna port configuration informationincludes at least antenna port information, and scrambling code IDinformation and codeword information of a UE-specific reference signalcorresponding to an antenna port. The antenna port information includesantenna port numbers and the quantity of antenna ports; the scramblingcode ID information includes scrambling code ID numbers; and thecodeword information includes codeword numbers and the quantity ofcodewords.

In another possible embodiment, the antenna port configurationinformation may further include one or any combination of the followingin addition to the above information: a length of an orthogonalspreading code of the UE-specific reference signal corresponding to anantenna port, and a mapping relationship between antenna portinformation and codeword information.

The antenna port configuration information may be obtained throughbroadcast signaling, or radio resource control (RRC, Radio ResourceControl) dedicated signaling, or media access control (MAC, Media AccessControl) layer signaling, or physical layer signaling, where thephysical layer signaling may be a PDCCH.

In this application, the type of the antenna port configurationinformation is determined according to a combination of specificparameters in the antenna port configuration information, for example,determined according to a combination of the antenna port information,and scrambling code ID information and codeword information of aUE-specific reference signal corresponding to an antenna port. The twoparameters, antenna port information and codeword information, mayrespectively include a quantity and value, for example, the quantity ofantenna ports, the quantity of codewords, antenna port numbers, andcodeword numbers; the parameter, scrambling code ID information of aUE-specific reference signal, includes a scrambling code ID number of aUE-specific reference signal. For example, for a combination of theparameters, if the D-PDCCH is transmitted on a port with antenna portnumber 7 (the quantity of antenna ports is 1), and the scrambling codeID number of a UE-specific reference signal is 0, and the codewordnumber is 0 (the quantity of codewords is 1), one type of antenna portconfiguration information may be obtained according to the abovecombination of parameters. For another combination of the parameters, ifthe D-PDCCH is transmitted on a port with antenna port number 8 (thequantity of antenna ports is 1), and the scrambling code ID number of aUE-specific reference signal is 1, and the codeword number is 1 (thequantity of codewords is 1), another type of antenna port configurationinformation may be obtained according to the above combination ofparameters. For another combination of the parameters, if the D-PDCCH istransmitted on ports with antenna port numbers 7 and 8 (the quantity ofantenna ports is 2), and the scrambling code ID number of a UE-specificreference signal is 0, and the codeword numbers are 0 and 1 (thequantity of codewords is 2), another type of antenna port configurationinformation may be obtained. In the following embodiments, for ease ofdescription, an example in which antenna port configuration informationis antenna port information is used in most embodiments, and in thiscase, assuming that the codeword information and scrambling code IDinformation of a UE-specific reference signal are both specific, forexample, a single codeword 0 and a scrambling code ID numbered 0.

Step 302: The UE determines a search space of the D-PDCCH, where thesearch space indicates a position to be detected, of at least onecandidate D-PDCCH of the D-PDCCH in time-frequency resources.

As in the prior art, the search space may be a block of resourcesdefined according to the CCE; in this case, a CCE is a smallest unit ofthe aggregation level. The search space may also be a block of resourcesdefined according to a resource block (RB, Resource Block) or an RBpair; in this case, an RB or an RB pair is a smallest unit of theaggregation level.

The search space may be obtained through the broadcast signaling, RRCdedicated signaling, or PDCCH transmitted by the base station side, ormay be determined and fed back by the UE itself to the base stationside.

The search space may be a determined position in the time-frequencyresources, that is, if the UE is scheduled, the eNB will definitelytransmit the D-PDCCH in the position. Correspondingly, the UE willdirectly detect the D-PDCCH in the position.

The search space may also be multiple candidate positions intime-frequency resources, that is, if the UE is scheduled, the eNB mayselect one from the candidate positions to transmit the D-PDCCH, and theUE will perform a blind detection of the D-PDCCH in the candidatepositions.

Step 303: The UE detects the D-PDCCH in the search space according tothe antenna port configuration information.

According to the above procedure,

in a possible embodiment, it is assumed that the eNB notifies a type ofantenna port configuration information of the D-PDCCH to the UE, andspecifically, notifies the UE that the D-PDCCH to be detected by the UEis on antenna port 7. Therefore, after receiving the information, the UEdetects D-PDCCH information on antenna port 7 according to thedetermined search space. In this way, after the UE learns information ofan antenna port for transmitting P-PDCCH, the UE may detect, on theantenna port, the D-PDCCH transmitted by the eNB, thereby ensuring datatransmission.

In another possible embodiment, it is assumed that the eNB notifies twotypes of antenna port configuration information of the D-PDCCH to theUE, and specifically, notifies the UE that the D-PDCCH to be detected bythe UE is on antenna port 7, or on antenna ports 7 and 8. Therefore,after receiving the information, the UE detects D-PDCCH information onantenna port 7 in a single-antenna-port manner, and also detects D-PDCCHinformation on antenna ports 7 and 8 in a two-antenna-port manneraccording to the determined search space.

It should be noted that the procedure in FIG. 3 may further include:

obtaining, by the UE, a mapping relationship between the antenna portconfiguration information and second information; in this case, the UEdetects the D-PDCCH in the search space according to the antenna portconfiguration information and the mapping relationship.

The mapping relationship between the antenna port configurationinformation and second information includes any one or any combinationof the following mapping relationships:

a mapping relationship between the antenna port configurationinformation and a DCI format used by the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and an aggregation level of the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and resources occupied by the D-PDCCH; and

a mapping relationship between the antenna port configurationinformation and scheduling information of each carrier borne in theD-PDCCH.

The following describes the above mapping relationships respectively.

A. The UE obtains a mapping relationship between the antenna portconfiguration information and at least one DCI format corresponding tothe D-PDCCH; in this case, the step of detecting the D-PDCCH in thesearch space includes: detecting, by the UE, the D-PDCCH in the searchspace according to the antenna port configuration information and themapping relationship. The antenna port configuration information mayinclude one type, and therefore the mapping relationship may be aone-to-one or one-to-many mapping relationship; or the antenna portconfiguration information may include at least two types, and thereforethe mapping relationship may be a many-to-one or many-to-many mappingrelationship.

Antenna port information is used as an example to describe how theantenna port configuration information corresponds to the used DCIformat.

When the mapping relationship is a one-to-one mapping relationship, itindicates that the D-PDCCH corresponding to a DCI format is transmittedin one antenna port configuration. For example, the D-PDCCHcorresponding to a DCI format is transmitted on antenna port 7.

When the mapping relationship is a one-to-many mapping relationship, itindicates that the D-PDCCHs corresponding to multiple DCI formats areall transmitted in one antenna port configuration. For example, theD-PDCCHs corresponding to two DCI formats are all transmitted on antennaport 7.

When the mapping relationship is a many-to-one mapping relationship, itindicates that the D-PDCCH corresponding to a DCI format may betransmitted in multiple antenna port configurations. For example, theD-PDCCH corresponding to a DCI format is transmitted on antenna port 7or 8. When the mapping relationship is a many-to-many mappingrelationship, it indicates that the D-PDCCHs corresponding to multipleDCI formats are transmitted in multiple antenna port configurations. Forexample, the D-PDCCHs corresponding to two DCI formats are alltransmitted on antenna port 7 or 8.

For ease of description, a symbol { } is introduced to indicate atransmission manner in which the D-PDCCH is transmitted in an antennaport configuration. Specifically, {7} indicates that the D-PDCCH istransmitted on antenna port 7 in a single-antenna port manner, that is,the UE detects the D-PDCCH on antenna port 7 in a single-antenna-portmanner; {7, 8} indicates that the D-PDCCH is transmitted on antennaports 7 and 8 in a two-antenna-port manner, that is, the UE detects theD-PDCCH on antenna ports 7 and 8 in a two-antenna-port manner. For otherantenna port numbers and the quantity of antenna ports in { },explanations are similar.

Specifically, the UE may map antenna ports of the D-PDCCH according todifferent DCI formats in a carrier configuration. It is assumed that theUE is configured with two carriers by the eNB, and in this case, the DCIformats to be detected by the UE include a first DCI format bearingscheduling information of a single carrier (the single carrier may be aprimary carrier), and a second DCI format bearing joint schedulinginformation of the two carriers. For the former, the UE may detect theD-PDCCH based on a single antenna port, for example, based on antennaport {7}, or perform blind detections for antenna ports {7} and {8}respectively. For the latter, there are the following three situations:

Situation 1: The UE may detect the D-PDCCH based on two antenna ports,for example, antenna ports {7, 8}, and in this case, no blind detectionis required for the antenna ports.

Situation 2: The UE performs blind detections for ports {7, 8} and {9,10} respectively based on two antenna ports. The benefit is that MU-MIMOtransmission of the D-PDCCH may be performed dynamically and flexibly inpairs with other UEs. Specifically, assuming that the D-PDCCH istransmitted by using 4 layers but the UE uses antenna ports {7, 8},another UE1 may use antenna ports {9, 10}. If the channel of the UE isnot applicable to pairing with UE1 but is applicable to pairing withUE2, but the ports of UE2 are configured as {7, 8}, the UE may use ports{9, 10} to perform pairing with UE2. In this way, by performing blinddetections for different ports, the flexibility of scheduling of theD-PDCCH by the system in MU-MIMO transmission is improved.

Situation 3: At least one DCI format corresponds to at least two antennaport configurations, where the quantities of antenna ports of the twoantenna port configurations are different. That is, the UE may performblind detections for configurations of different quantities of antennaport. Specifically, for the second DCI format, the antenna ports thatmay be configured are {7, 8} and {7}. The benefit is that in a subframe,the eNB needs to transmit the D-PDCCH corresponding to the second DCIformat to schedule two carriers of the UE. If the channel can supporttwo-layer transmission at this time, the eNB may use antenna ports {7,8} to transmit the second DCI format. If the channel can support onlyone-layer transmission at this time, the eNB may fall back to antennaport {7} to transmit the second DCI format. Therefore, the UE maydynamically adapt to a channel change and complete data transmission byblindly detection for configurations of different quantities of port.

Further, in another embodiment, when the first DCI format corresponds tothe first antenna port configuration information, the second DCI formatcorresponds to the second antenna port configuration information, andthe payload size of the D-PDCCH corresponding to the first DCI format isequal to the payload size of the D-PDCCH corresponding to the second DCIformat and the payload sizes may be distinguished by using informationin the two DCI formats, the D-PDCCH corresponding to the first DCIformat and the D-PDCCH corresponding to the second DCI format may sharethe first and second antenna port configuration information. Forexample, if the first DCI format corresponds to antenna port 7, thesecond DCI format corresponds to antenna port 8, and payload sizes ofthe two DCI formats are equal and are distinguished by using a headerbit in the two DCI formats, both the D-PDCCHs corresponding to the firstDCI format and second DCI format can be transmitted on port 7 and port8. Correspondingly, the UE needs to detect the D-PDCCHs corresponding tothe two DCI formats on both ports 7 and 8, and distinguish the DCIformats by using the header bit in the two DCI formats.

The above solution is extended to a carrier dimension, and the D-PDCCHcorresponding to the DCI includes information indicating carrierscheduling, for example, a carrier indicator field specificallyindicates which one or which several carriers are scheduled.Specifically, when the D-PDCCH corresponding to at least two DCI formatsscheduling a first carrier corresponds to the first antenna portconfiguration information, the D-PDCCH corresponding to at least two DCIformats scheduling a second carrier corresponds to the second antennaport configuration information, and if at least one first DCI format inthe at least two DCI formats scheduling the first carrier has the samepayload size as at least one second DCI format in the at least two DCIformats scheduling the second carrier, the D-PDCCHs corresponding to thefirst DCI format and second DCI format may share the first and secondantenna port configuration information. For example, if DCI format 1 andDCI format 2 scheduling the first carrier correspond to antenna port 7,DCI format 3 and DCI format 4 scheduling the second carrier correspondto antenna port 8, and DCI format 1 has the same payload size as DCIformat 3, the D-PDCCHs corresponding to DCI format 1 and DCI format 3can all be transmitted on port 7 and port 8. Correspondingly, the UEneeds to detect the D-PDCCHs corresponding to DCI format 1 and DCIformat 3 on both ports 7 and 8 and distinguish DCI format 1 and DCIformat 3 by using a carrier indicator field. However, DCI format 2scheduling the first carrier may be transmitted on only port 7, and DCIformat 4 scheduling the second carrier may be transmitted on only port 8(assuming that payload sizes of DCI format 2 and DCI format 4 are notequal). In the above solution, different DCI formats having the samepayload size or the DCI formats corresponding to different carriers mayshare antenna port configuration information, which does not result inan increase of the count of extra blind detections of the D-PDCCH by theUE.

B. The UE obtains a mapping relationship between the antenna portconfiguration information and an aggregation level of the D-PDCCH; inthis case, the step of detecting the D-PDCCH in the search spaceincludes: detecting, by the UE, the D-PDCCH in the search spaceaccording to the antenna port configuration information and the mappingrelationship. The antenna port configuration information may include onetype, and therefore the mapping relationship may be a one-to-one orone-to-many mapping relationship; or the antenna port configurationinformation may include at least two types, and therefore the mappingrelationship may be a many-to-one or many-to-many mapping relationship.

For example, D-PDCCHs of aggregation levels 1 and 4 are transmitted onantenna port {7}, and D-PDCCHs of aggregation levels 2 and 8 aretransmitted on antenna port {8}. In this way, the D-PDCCH may bedetected according to the mapping relationship between the antenna portused in transmission and the aggregation level.

C. The UE obtains a mapping relationship between the antenna portconfiguration information and resources occupied by the D-PDCCH; in thiscase, the step of detecting the D-PDCCH in the search space includes:detecting, by the UE, the D-PDCCH in the search space according to theantenna port configuration information and the mapping relationship. Theresources occupied by the D-PDCCH include one or more of time,frequency, and code resources. The antenna port configurationinformation may include one type, and therefore the mapping relationshipmay be a one-to-one or one-to-many mapping relationship; or the antennaport configuration information may include at least two types, andtherefore the mapping relationship may be a many-to-one or many-to-manymapping relationship.

Antenna port information is used as an example to describe how theantenna port configuration information corresponds to resources.

Using time-domain resources as an example, when the current subframe isa type-1 subframe, the D-PDCCH is transmitted on antenna port 7, andwhen the current subframe is a type-2 subframe, the D-PDCCH istransmitted on antenna port 8. The type-1 and type-2 subframes maycorrespond to an odd subframe number and an even subframe numberrespectively, that is, the subframe corresponding to the odd subframenumber is a type-1 subframe, and the subframe corresponding to the evensubframe number is a type-2 subframe. Or the type-1 and type-2 subframesare distinguished by using T as a period; from subframe 1 to subframe T,antenna port 7 is used for transmission; from subframe T+1 to subframe2T, antenna port 8 is used for transmission; from subframe 2T+1 tosubframe 3T, antenna port 7 is used for transmission; from subframe 3T+1to subframe 4T, antenna port 8 is used for transmission, and so on,where subframe 1 to subframe T, and subframe 2T+1 to subframe 3T aretype-1 subframes, and subframe T+1 to subframe 2T, and subframe 3T+1 tosubframe 4T are type-2 subframes.

In brief, the UE obtains a mapping relationship between the antenna portconfiguration information and the time-domain resources where theD-PDCCH is located, specifically, for example, port 7 corresponds to anodd subframe, and port 8 corresponds to an even subframe.

The UE detects the D-PDCCH on port 7 in the case of an odd subframeaccording to the above mapping relationship; and detects the D-PDCCH onport 8 in the case of an even subframe.

The antenna port configuration information of the D-PDCCH may furthercorrespond to a candidate detection position in an RB or in a CCE or ata specific aggregation level. Specifically, the antenna portconfiguration information may include one type, and therefore themapping relationship may be a one-to-one or one-to-many mappingrelationship; or the antenna port configuration information may includeat least two types, and therefore the mapping relationship may be amany-to-one or many-to-many mapping relationship.

Specifically, using a candidate detection position at a specificaggregation level as an example, assuming that 6 positions of candidateD-PDCCHs in the search space of aggregation level 1 are P1, P2, . . . ,and P6, the UE may detect the D-PDCCH in the time-frequency positions ofP1, P2, and P3 of antenna port 7 and detect the D-PDCCH in thetime-frequency positions of P4, P5, and P6 of antenna port 8. For searchspaces of other aggregation levels and other mapping relationships,similar processing is performed, which is not limited herein. Foranother example, different antenna port configurations of the D-PDCCHmay correspond to different time-frequency domain search spaces. Forexample, antenna port 7 corresponds to search space 1, and antenna port8 corresponds to search space 2. The specific search space may bedetermined by using a preset rule, for example, by using a UEID andantenna port information. In this case, the UE may detect the D-PDCCH insearch space 1 of antenna port 7, and detect the D-PDCCH in search space2 of antenna port 8. Preferably, time-frequency resources in the searchspaces corresponding to different antenna configurations do not overlap.For example, P1, P2, and P3 do not overlap with P4, P5, and P6, ortime-frequency resources in search space 1 and search space 2 do notoverlap, so that it is convenient for the UE to perform parallelprocessing respectively according to different antenna ports, therebyreducing the implementation complexity on the UE side. Optionally, P1,P2, and P3 may also overlap with P4, P5, and P6, that is, only threecandidate positions are occupied on the time-frequency resources, butthe positions are spatially at multiple layers.

The mapping relationship between other frequency or code resources orthe combination of resources, and the antenna port configurationinformation is similar to that of the above time-frequency resources,and is not further described herein.

D. The UE obtains a mapping relationship between the antenna portconfiguration information and scheduling information of each carrierborne in the D-PDCCH; in this case, the step of detecting the D-PDCCH inthe search space includes: detecting, by the UE, the D-PDCCH in thesearch space according to the antenna port configuration information andthe mapping relationship. The antenna port configuration information mayinclude one type, and therefore the mapping relationship may be aone-to-one or one-to-many mapping relationship; or the antenna portconfiguration information may include at least two types, and thereforethe mapping relationship may be a many-to-one or many-to-many mappingrelationship.

Antenna port information is used as an example to describe how antennaport configuration information corresponds to scheduling information ofeach carrier. For example, the eNB configures two carriers for the UE,which are CC1 and CC2 respectively. The mapping relationship may be:scheduling information scheduling CC1 is transmitted on antenna port 7,and scheduling information scheduling CC2 is transmitted on antenna port8. Specifically, when the eNB uses two D-PDCCHs to schedule CC1 and CC2respectively, scheduling information of CC1 may correspond to codeword1, and scheduling information of CC2 may correspond to codeword 2, wherecodeword 1 corresponds to antenna port 7, and codeword 2 corresponds toantenna port 8.

Further, scheduling information may be divided into schedulinginformation shared by CC1 and CC2 (for example, a modulation and codingscheme field), and respective independent scheduling information of CC1and CC2 (for example, a resource allocation field); the respectiveindependent scheduling information of CC1 and CC2 is transmitted onantenna ports 7 and 8 respectively, and the scheduling informationshared by CC1 and CC2 is transmitted on only one of antenna ports 7 and8.

The antenna port configuration information may also have a mappingrelationship with the quantity of scheduled carriers. For example, if aD-PDCCH bears scheduling information of a carrier, the UE may detect theD-PDCCH based on a single antenna port, where the port configuration maybe {7} or {8}; if a D-PDCCH bears joint scheduling information of two orthree carriers, the UE may detect the D-PDCCH based on two antennaports, where the port configuration may be {7, 8} or {9, 10}; if aD-PDCCH bears joint scheduling information of four or five carriers, theUE may detect the D-PDCCH based on four antenna ports, where the portconfiguration may be {7, 8, 9, 10} or {11, 12, 13, 14}.

It should be noted that on the basis of the procedure shown in FIG. 3,one or any combination of the A, B, C, and D may be included; inaddition, the A, B, C, and D are in no strict order. That is, on thebasis of the procedure shown in FIG. 3, A, or A and C, or A, C, and Dmay be included, and so on. When more than two mapping relationships areincluded, the mapping relationships may be transferred. For example, ifboth A and B are included, the mapping relationship between the antennaport configuration information and at least one DCI format correspondingto the D-PDCCH in A, and the mapping relationship between the antennaport configuration information and an aggregation level of the D-PDCCHin B, coexist. In this case, it may also be understood that a mappingrelationship exists between the antenna port configuration information,at least one DCI format, and the aggregation level.

For example, the D-PDCCH corresponding to the first DCI format istransmitted by using aggregation levels 1 and 4, and is transmitted onantenna port 7; the D-PDCCH corresponding to the second DCI format istransmitted by using aggregation levels 2 and 8, and is transmitted onantenna port 8. In this way, the mapping relationship between the DCIformat, the aggregation level, and antenna port information isimplemented.

All the above embodiments are described by using antenna portinformation as an example. The following uses an example in whichantenna port configuration information is antenna port information and acodeword number (the scrambling code ID is specific, for example, ascrambling code ID number 0), so as to describe how the antenna portinformation and the codeword number correspond to scheduling informationof each carrier borne in the D-PDCCH:

For example, assuming that the D-PDCCH uses two codewords (the codewordnumbers are codeword 1 and codeword 2) for transmission and that thecarriers currently configured for the UE are component carrier (CC,Component Carrier) 1, CC2, and CC3, the mapping relationship between thecodeword numbers and the DCI formats may be: the first DCI formatcorresponding to scheduling information scheduling CC1 corresponds tocodeword 1, and the second DCI format corresponding to the jointscheduling information scheduling CC2 and CC3 corresponds to codeword 2.Further, codeword 1 corresponds to antenna port 7, and codeword 2corresponds to antenna port 8. Therefore, all scheduling informationscheduling CC1, CC2, and CC3 may share same time-frequency resourcesthrough MIMO transmission of multiple codewords, thereby increasing theefficiency of resource utilization in D-PDCCH transmission. Preferably,the CC1 corresponding to codeword 1 may be a primary carrier, that is,the DCI format corresponding to the primary carrier separately occupiesa codeword to improve the reception performance of the D-PDCCHscheduling the primary carrier.

For another example, antenna port configuration information maycorrespond to at least two parts of control information in the D-PDCCHcorresponding to one DCI format, where the specific mapping relationshipmay be: the antenna port configuration information includes one type,and therefore the mapping relationship may be a one-to-one orone-to-many mapping relationship; or the antenna port configurationinformation may include at least two types, and therefore the mappingrelationship may be a many-to-one or many-to-many mapping relationship.Specifically, assuming that control information in the D-PDCCHcorresponding to one DCI format is divided into two parts, where thefirst part includes resource allocation control information, and thesecond part includes control information except the resource allocationcontrol information (other dividing methods are not limited), the firstpart of control information may correspond to codeword 1, and the secondpart of control information may correspond to codeword 2. Further,codeword 1 corresponds to antenna port 7, and codeword 2 corresponds toantenna port 8. The UE detects corresponding codeword 1 and codeword 2on antenna ports 7 and 8 respectively, obtains the two parts of controlinformation by decoding, and forms a piece of complete DCI by using thetwo parts of control information. With respect to this case, uplinkacknowledgement/negative acknowledgement (ACK/NACK,ACKnowledge/Non-ACKnowledge) is designed specially.

Specifically, it is assumed that the D-PDCCH corresponding to one DCIformat uses two codewords (codeword 0 and codeword 1) for transmission,where the two codewords may correspond to an ACK/NACK (ACK/NACK0 andACK/NACK1) respectively. A specific mapping method may be configuring byusing explicit signaling or mapping by using an implicit rule. A mappingmethod is that an ACK/NACK resource is mapped by using a control channelelement (which may be a CCE, an RB, or an RB pair) number and an antennaport number, or a control channel element number and a codeword number,for example, an ACK/NACK0 resource corresponds to a control channelelement number and antenna port number 7 (corresponding to codeword 0)of the D-PDCCH, and an ACK/NACK1 resource corresponds to a controlchannel element number and antenna port number 8 (corresponding tocodeword 1) of the D-PDCCH. One ACK/NACK (such as ACK/NACK0corresponding to a minimum antenna number or codeword number occupied bythe D-PDCCH) corresponds to the feedback of the PDSCH scheduled by theD-PDCCH, that is, if both two codewords of the D-PDCCH are decodedcorrectly, correct decoding and incorrect decoding of the PDSCHcorrespond to ACK and NACK feedback of the ACK/NACK0 respectively, andthe ACK/NACK1 is not transmitted in this case. Another ACK/NACK(ACK/NACK1) corresponds to the feedback of the D-PDCCH itself. Onemanner is that if codeword 0 corresponding to the D-PDCCH is decodedcorrectly but codeword 1 is decoded incorrectly, the ACK/NACK1 is anACK; if codeword 1 corresponding to the D-PDCCH is decoded correctly butcodeword 0 is decoded incorrectly, the ACK/NACK1 is a NACK, and viceversa. Particularly, if both the two codewords of the D-PDCCH aredecoded incorrectly, the UE does not transmit the ACK/NACK0 andACK/NACK1. In this method, if a part of codewords of a D-PDCCH aretransmitted correctly, only the other part of codewords that aretransmitted incorrectly need to be retransmitted, which improves theretransmission efficiency and improves the performance of the D-PDCCH.

For another example, a downlink scheduling grant (DL_grant) and anuplink scheduling grant (UL_grant) respectively correspond to differentantenna port configuration information, for example, correspond todifferent codeword numbers.

It should be noted that the mapping relationships involved in the A, B,C, and D may be obtained through broadcast signaling, or RRC dedicatedsignaling, or MAC layer signaling, or physical layer signaling, wherethe physical layer signaling may be a PDCCH.

It should be noted that the method shown in FIG. 3 may further include:obtaining, by the UE, an aggregation level corresponding to the D-PDCCHand the count of detections of a candidate D-PDCCH corresponding to theaggregation level. In this way, when the UE detects the D-PDCCH in thesearch space according to the antenna port configuration information, ifthe count of detections is reached, the detection is stopped. That is,the detecting the D-PDCCH in the search space includes: detecting theD-PDCCH in the search space according to the obtained aggregation levelcorresponding to the D-PDCCH and the count of detections of thecandidate D-PDCCH corresponding to the aggregation level.

The aggregation level of the D-PDCCH may include 1, 2, 4, and 8 basicunits of the control channel, where the basic unit of the controlchannel may be a CCE, an RB, or an RB pair. The count of searches of thecandidate D-PDCCH corresponding to the four aggregation levels 1, 2, 4,and 8 may be 6, 6, 2, and 2 respectively, that is, the setting in theexisting system is inherited. Or the aggregation levels in each antennaport configuration and the corresponding information about the count ofdetections of the candidate D-PDCCH may be configured for the UE throughthe signaling transmitted by the eNB, where the signaling may be RRCdedicated signaling or physical layer signaling (such as a PDCCH).

Specifically, when the UE detects an antenna port (such as port 7), theUE further needs to blindly detect different aggregation levels. Toensure that the count of blind detections by the UE is not greater thanthat in the existing system (for example, in the existing system, if twoDCI formats are detected, the total count of blind detections does notexceed 32), the count of searches of the candidate D-PDCCH correspondingto the aggregation level and/or each aggregation level may be limited.In a possible embodiment, the UE needs to detect two antenna portconfigurations, that is, ports {7} and {8}. In this case, for each DCIformat, the number of aggregation levels to be detected may be limitedto three. For example, for the DCI format having a light payload (forexample, scheduling information transmitted by a single codeword bearinga single carrier, specifically as shown in DCI formats 0 and 1A), threeaggregation levels 1, 2, and 4 using an RB as a unit may be detected,and the count of searches of the candidate D-PDCCH corresponding to eachaggregation level may be limited to 4, 2, and 2. For a DCI format havinga heavy payload (for example, scheduling information bearing multiplecarriers or transmitted by multiple codewords, specifically as shown inDCI format 2C), three aggregation levels 1, 2, and 4 using an RB as aunit may be detected, and the count of searches of the candidate D-PDCCHcorresponding to each aggregation level may be limited to 4, 2, and 2.Therefore, the total count of blind detections by the UE is 2 antennaport configurations*2 DCI formats*(4+2+2)=32, which is not greater thanthe count of blind detections by the UE in the existing system. Otherlimiting methods are not restricted.

Particularly, in another possible case, because a rate matching moduleafter the payload of a D-PDCCH is encoded uses a circular buffer(circular buffer) mechanism, in the case of some payload sizes of theD-PDCCH, when a high aggregation level of the control channel is used totransmit the D-PDCCH (using the aggregation level of two RBs as anexample, assuming that the RBs forming the D-PDCCH are RB1 and RB2, andthat the mapping rule of an ACK/NACK uses the first RB, that is, anACK/NACK channel implicitly corresponding to RB1), and the search spaceof the aggregation level of one RB and the search space of theaggregation level of two RBs overlap, the UE may also correctly detectthe D-PDCCH by using RB2 of one aggregation level. However, in thiscase, the UE feeds back the ACK/NACK by using the ACK/NACK channelimplicitly corresponding to RB2, and the eNB detects the ACK/NACK on theACK/NACK channel implicitly corresponding to RB1. As a result, anACK/NACK channel detection error and collision may occur. An extensiblecase is that the UE needs to blindly detect multiple antenna portconfigurations, for example, detect two antenna port configurations, andspecifically a single antenna port 8 and two antenna ports 7 and 8,where the resources detected in the two configurations overlap, forexample, search spaces overlap. In this case, in the case of some fixedpayload sizes of the D-PDCCH, when two antenna ports 7 and 8 are used totransmit the D-PDCCH (assuming that an ACK/NACK corresponds to antennaport 7 of a small number), the UE may also correctly detect the D-PDCCHby detecting the D-PDCCH by using a single antenna port 8, and the UEuses the ACK/NACK channel corresponding to port 8 to feed back theACK/NACK, while the eNB detects the ACK/NACK on the ACK/NACK channelcorresponding to port 7. As a result, a detection error and collision ofthe ACK/NACK channel may occur.

A solution to the above problem is: once the eNB and the UE find thecase of a specific payload size of the D-PDCCH, for example, the casewhere the payload size of the D-PDCCH is 24 or 26 (excluding a CRC bit),the eNB and the UE add 1 bit to the payload size of the D-PDCCH, so asto implement transmission and reception of the D-PDCCH. For example, 1bit is added to the D-PDCCH with the payload size 24 so that the payloadsize is 25, and 1 bit is added to the D-PDCCH with the payload size 26so that the payload size is 27, thereby avoiding occurrence of thespecific payload.

In the above solution, the D-PDCCH is a DL_grant. The solution may alsobe similarly extended to the case where the D-PDCCH is a UL_grant.Specifically, for the UL_grant of a specific fixed payload size, 1 bitalso needs to be added to the payload size to avoid the collision of aPHICH channel (the PHICH is used to transmit a downlink ACK/NACK),because a PHICH channel resource has a mapping relationship with an RBor an RB pair or an antenna port occupied by the D-PDCCH of theUL_grant.

The solution for the D-PDCCH of the specific payload size may bedirectly applied to the embodiment shown in FIG. 3 or the aboveembodiments.

With the method provided by the embodiment of the present invention, aUE can detect a D-PDCCH, and therefore data transmission is ensured.Furthermore, a blind detection of a PDCCH by the UE based ontime-frequency resources in an existing system is extended to a spatialdimension, that is, an antenna port, thereby increasing the efficiencyof resource utilization, so that the D-PDCCH can be detected in thespatial dimension. In this way, a D-PDCCH detection method is provided,the flexibility of scheduling of the D-PDCCH in MU-MIMO is improved, andthe reception performance of the PDCCH is improved; in addition, it isensured that the count of blind detections by the UE is not greater thanthat in the existing system, that is, the implementation complexity ofthe UE is not increased.

An embodiment of the present invention further provides another methodfor detecting information. Referring to FIG. 4, the method is used on abase station side, and the method may include:

Step 401: A base station configures at least one type of antenna portconfiguration information occupied by a D-PDCCH for a UE.

Step 402: The base station determines search space information of theD-PDCCH, where the search space indicates at least one position of theD-PDCCH in time-frequency resources.

Step 403: The base station transmits the D-PDCCH in the search space tothe UE according to the at least one type of configuration informationof an antenna port occupied by the D-PDCCH to be detected which isconfigured for the UE.

The base station further obtains a mapping relationship between theantenna port configuration information and second information, andconfigures the obtained mapping relationship for the UE.

The mapping relationship between the antenna port configurationinformation and second information includes any one or any combinationof the following mapping relationships:

a mapping relationship between the antenna port configurationinformation and a DCI format used by the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and an aggregation level of the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and resources occupied by the D-PDCCH; and

a mapping relationship between the antenna port configurationinformation and scheduling information of each carrier borne in theD-PDCCH.

The antenna port configuration information includes one type, and themapping relationship is a one-to-one or one-to-many mappingrelationship; or

the antenna port configuration information includes at least two types,and the mapping relationship is a many-to-one or many-to-many mappingrelationship.

The foregoing method may further include:

configuring, by the base station, an aggregation level corresponding tothe D-PDCCH and a count of detections of a candidate D-PDCCHcorresponding to the aggregation level for the UE, so that the UEdetects the D-PDCCH in the search space according to the obtainedaggregation level corresponding to the D-PDCCH and the count ofdetections of the candidate D-PDCCH corresponding to the aggregationlevel.

With the method provided by the embodiment of the present invention, aUE can detect a D-PDCCH, and therefore data transmission is ensured.Furthermore, a blind detection of a PDCCH by the UE based ontime-frequency resources in an existing system is extended to a spatialdimension, that is, an antenna port, thereby increasing the efficiencyof resource utilization, so that the D-PDCCH can be detected in thespatial dimension. In this way, a D-PDCCH detection method is provided,the flexibility of scheduling of the D-PDCCH in MU-MIMO is improved, andthe reception performance of the PDCCH is improved; in addition, it isensured that the count of blind detections by the UE is not greater thanthat in the existing system, that is, the implementation complexity ofthe UE is not increased.

An embodiment of the present invention further provides a userequipment. Referring to FIG. 5, the user equipment specificallyincludes:

an obtaining unit 501, adapted to obtain at least one type ofconfiguration information of an antenna port occupied by a D-PDCCH,which is configured on a base station side;

a determining unit 502, adapted to determine a search space of theD-PDCCH, where the search space indicates a position to be detected, ofat least one candidate D-PDCCH of the D-PDCCH in time-frequencyresources; and

a detecting unit 503, adapted to detect the D-PDCCH in the search spaceaccording to the antenna port configuration information.

For the user equipment shown in FIG. 5:

the obtaining unit 501 is further adapted to obtain a mappingrelationship between the antenna port configuration information andsecond information;

the detecting unit 503 is further adapted to detect the D-PDCCH in thesearch space according to the antenna port configuration information andthe mapping relationship; and

the mapping relationship between the antenna port configurationinformation and second information includes any one or any combinationof the following mapping relationships:

a mapping relationship between the antenna port configurationinformation and a DCI format used by the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and an aggregation level of the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and resources occupied by the D-PDCCH; and

a mapping relationship between the antenna port configurationinformation and scheduling information of each carrier borne in theD-PDCCH.

The antenna port configuration information includes one type, and themapping relationship is a one-to-one or one-to-many mappingrelationship; or

the antenna port configuration information includes at least two types,and the mapping relationship is a many-to-one or many-to-many mappingrelationship.

The antenna port configuration information includes at least antennaport information, and scrambling code ID information and codewordinformation of a UE-specific reference signal corresponding to anantenna port; the antenna port configuration information furtherincludes one or any combination of the following: a length of anorthogonal spreading code of the UE-specific reference signalcorresponding to an antenna port, and a mapping relationship betweenantenna port information and codeword information.

For the user equipment shown in FIG. 5:

the obtaining unit 501 is further adapted to obtain an aggregation levelcorresponding to the D-PDCCH and the count of detections of a candidateD-PDCCH corresponding to the aggregation level; and

the detecting unit 503 is further adapted to detect the D-PDCCH in thesearch space according to the obtained aggregation level correspondingto the D-PDCCH and the count of detections of the candidate D-PDCCHcorresponding to the aggregation level.

With the terminal provided by the embodiment of the present invention, aUE can detect a D-PDCCH, and therefore data transmission is ensured.Furthermore, a blind detection of a PDCCH by the UE based ontime-frequency resources in an existing system is extended to a spatialdimension, that is, an antenna port, thereby increasing the efficiencyof resource utilization, so that the D-PDCCH can be detected in thespatial dimension. In this way, a D-PDCCH detection method is provided,the flexibility of scheduling of the D-PDCCH in MU-MIMO is improved, andthe reception performance of the PDCCH is improved; in addition, it isensured that the count of blind detections by the UE is not greater thanthat in the existing system, that is, the implementation complexity ofthe UE is not increased.

An embodiment of the present invention further provides a base station.Referring to FIG. 6, the base station specifically includes:

a configuring unit 601, adapted to configure at least one type ofconfiguration information of an antenna port occupied by a D-PDCCH for aUE;

a search space determining unit 602, adapted to determine search spaceinformation of the D-PDCCH; and

a transmitting unit 603, adapted to transmit the D-PDCCH in the searchspace to the UE according to the at least one type of antenna portconfiguration information occupied by the D-PDCCH which is configuredfor the UE.

In another possible embodiment, in addition to the configuring unit 701,search space determining unit 702, and transmitting unit 703, the basestation may further include:

an obtaining unit 704, adapted to obtain a mapping relationship betweenthe antenna port configuration information and second information, where

the transmitting unit 703 is further adapted to configure the obtainedmapping relationship for the UE; and

the mapping relationship between the antenna port configurationinformation and second information includes any one or any combinationof the following mapping relationships:

a mapping relationship between the antenna port configurationinformation and a DCI format used by the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and an aggregation level of the D-PDCCH;

a mapping relationship between the antenna port configurationinformation and resources occupied by the D-PDCCH; and

a mapping relationship between the antenna port configurationinformation and scheduling information of each carrier borne in theD-PDCCH.

The antenna port configuration information configured by the firstconfiguring unit includes one type, and the mapping relationshipobtained by the obtaining unit is a one-to-one or one-to-many mappingrelationship;

or

the antenna port configuration information configured by the firstconfiguring unit includes at least two types, and the mappingrelationship obtained by the obtaining unit is a many-to-one ormany-to-many mapping relationship.

For the base station in FIG. 6 and FIG. 7,

the configuring unit is further adapted to configure an aggregationlevel corresponding to the D-PDCCH and a count of detections of acandidate D-PDCCH corresponding to the aggregation level for the UE, sothat the UE detects the D-PDCCH in the search space according to theobtained aggregation level corresponding to the D-PDCCH and the count ofdetections of the candidate D-PDCCH corresponding to the aggregationlevel.

With the base station provided by the embodiment of the presentinvention, a UE can detect a D-PDCCH, and therefore data transmission isensured. Furthermore, a blind detection of a PDCCH by the UE based ontime-frequency resources in an existing system is extended to a spatialdimension, that is, an antenna port, thereby increasing the efficiencyof resource utilization, so that the D-PDCCH can be detected in thespatial dimension. In this way, a D-PDCCH detection method is provided,the flexibility of scheduling of the D-PDCCH in MU-MIMO is improved, andthe reception performance of the PDCCH is improved; in addition, it isensured that the count of blind detections by the UE is not greater thanthat in the existing system, that is, the implementation complexity ofthe UE is not increased.

The embodiments of the UE terminal and base station side are describedbriefly because the embodiments of the UE terminal and base station sideare basically similar to the method embodiments. Therefore, for relatedinformation, reference may be made to the part of the description of themethod embodiments.

Embodiment 2

As can be known from the above description, in an existing LTE system, asubframe is a smallest time unit scheduled by an eNB, each subframeincludes two timeslots, and each timeslot includes seven symbols. For aUE scheduled in a subframe, the subframe includes a physical downlinkcontrol channel (PDCCH) of the UE. The PDCCH is dispersed to the wholesystem bandwidth in a frequency domain through interleaving processing.In a time domain, the PDCCH is borne in first n symbols of the subframe,where n may be one of 1, 2, and 3, or one of 2, 3, and 4 (in a casewhere the system bandwidth is 1.4 MHz). Specifically, the PDCCH isnotified by two bits borne in a PCFICH, where the n symbols indicate acontrol channel region. A downlink data channel PDSCH may be scheduledby the PDCCH, and the PDCCH and the scheduled PDSCH are in the samesubframe. The PDCCH occupies the first several symbols, and the PDSCHoccupies the following several symbols.

When the UE performs a detection, the UE first detects a physicalcontrol format indicator channel (PCFICH, Physical Control FormatIndicator Channel), and learns which several symbols the PDCCH occupies,and then detects the PDCCH, and correspondingly receives, according toscheduling information in the PDCCH, the PDSCH scheduled by the PDCCH.As can be seen from the prior art, when a PCFICH detection error occurs,it is impossible that the UE can detect its own PDCCH; conversely, whenthe UE detects its own PDCCH successfully, it indicates that the PCFICHis definitely detected correctly. This process may mean that the PDCCHdetection by the UE is a verification of the PCFICH detection.

In an LTE system of a later release, technologies such as carrieraggregation, multi-user MIMO, and CoMP will be introduced. In addition,a heterogeneous network scenario will be widely applied. All these willlead to a capacity limitation on the PDCCH. Therefore, a PDCCH based onchannel information precoding will be introduced. This PDCCH will bedemodulated based on a UE-specific reference signal, and the UE-specificreference signal may also be referred to as a dedicated reference signal(DRS). Therefore, the PDCCH demodulated based on the DRS is hereinafterbriefed as a D-PDCCH. Because D-PDCCH resources are located in a PDSCHregion, and the D-PDCCH and the PDSCH scheduled by the D-PDCCH aredivided by frequencies. An encountered problem is how to determine atime-domain start symbol of the D-PDCCH and a time-domain start symbolof the PDSCH scheduled by the D-PDCCH.

At present, a solution is that, for a simple implementation, in thefirst timeslot of a subframe, the UE receives the D-PDCCH based on thefixed time-domain start symbol, for example, the maximum value of thePCFICH, and further receives the D-PDCCH behind the control channelregion. Next, the UE receives the PDSCH according to schedulinginformation in the received D-PDCCH, in the same subframe, that is, thesubframe where the D-PDCCH is located. The time-domain start symbol ofthe PDSCH may be obtained by the detection of the PCFICH. Specifically,according to the detection of the PCFICH, if it is determined that thecontrol channel region is n symbols, the UE receives the PDSCH from the(n+1)^(th) symbol. The problem is: if a PCFICH detection error occurs,and the D-PDCCH is received correctly, the UE incorrectly finds thestart point of the PDSCH, resulting in a detection error of the PDSCH;further, due to the error of the start point of data, the data cannot berecovered by a subsequent retransmission combination mechanism, finallyresulting in loss of the PDSCH data packet at the physical layer.

In view of the above technical problem, Embodiment 2 of the presentinvention provides a method for receiving information, so as to solvethe problem of incorrectly finding the start point of the PDSCHresulting from a PCFICH detection error, thereby improving thetransmission efficiency of the system.

A method for receiving a PDSCH includes:

in a first timeslot of a subframe, receiving, by a UE, a D-PDCCH byusing symbol m as a time-domain start symbol; and

receiving, by the UE according to downlink scheduling information bornein the D-PDCCH and by using symbol n as a time-domain start symbol, aPDSCH scheduled by the D-PDCCH.

The D-PDCCH and the PDSCH are on a same carrier.

The value of the symbol m is predefined, or notified through broadcastsignaling or RRC dedicated signaling or physical layer signaling, wherethe physical layer signaling is a PDCCH.

Preferably, for the system bandwidth except the system bandwidth 1.4MHz, the time-domain start symbol of the D-PDCCH in the first timeslotof a subframe may be a predefined fourth symbol. Based on theassumption, optionally, if the value of the PCFICH is 1 or 2, the secondand third symbols in the frequency-domain resource positions of theD-PDCCH are idle, or the third symbol is idle. In this case, the idlesymbols may be used to bear other information, for example, PHICHresources.

The value of the n is predefined, or notified through RRC dedicatedsignaling or MAC layer signaling or physical layer signaling, where thephysical layer signaling is specifically the D-PDCCH or other PDCCHs,for example, another PDCCH indicating the D-PDCCH information.

Optionally, a bit or CRC mask in the D-PDCCH is used to notify thetime-domain start symbol of the PDSCH scheduled by the D-PDCCH, forexample, 2 bits may indicate that the PDSCH starts from the second,third, fourth, or fifth symbol.

Optionally, the RRC dedicated signaling is used to configure thetime-domain start symbol of the PDSCH scheduled by the D-PDCCH.

Optionally, a first-level PDCCH is used to notify the time-domain startsymbol of the PDSCH scheduled by the D-PDCCH. The first-level PDCCH isused to notify information such as resources of the D-PDCCH.

A specific example is as follows:

Assuming that the downlink system bandwidth is not 1.4 MHz, the controlchannel region occupies at most three symbols. For a simpleimplementation, the start time-domain symbol of the D-PDCCH may be apredefined fourth symbol, or may be configured through broadcastsignaling or RRC signaling or MAC layer signaling or physical layersignaling (such as a PDCCH). Therefore, the UE receives the D-PDCCHaccording to the start symbol of the D-PDCCH, and receives, according todownlink scheduling information borne in the D-PDCCH, the PDSCHscheduled by the D-PDCCH. When receiving the PDSCH, to avoid the impactcaused by the PCFICH detection error, the UE cannot determine thetime-domain start symbol of the PDSCH according to the quantity ofcontrol channel region symbols obtained by detecting the PCFICH, butreceives the PDSCH through the predefined start symbol of the PDSCH(such as the fourth symbol), or through the start symbol of the PDSCHnotified by broadcast signaling or RRC signaling or MAC layer signalingor physical layer signaling (such as another PDCCH indicating theD-PDCCH information, or the D-PDCCH).

With the above method for receiving information, the problem that thestart point of the PDSCH is incorrectly detected due to a PCFICHdetection error is solved, and the transmission efficiency of the systemis improved.

An embodiment of this application further provides a method fortransmitting a PDSCH, including:

in a first timeslot of a subframe, transmitting, by an eNB, a D-PDCCH toa UE by using symbol m as a time-domain start symbol, where the D-PDCCHindicates a time-domain start symbol of a PDSCH scheduled by theD-PDCCH,

so that the UE detects, according to downlink scheduling informationborne in the D-PDCCH and the time-domain start symbol information, thePDSCH scheduled by the D-PDCCH.

The time-domain start symbol information of the PDSCH may be furthernotified to the UE through broadcast signaling or RRC signaling or MAClayer signaling or physical layer signaling (such as another PDCCHindicating the D-PDCCH information) transmitted by the eNB.

With the above method for transmitting information, the problem that thestart point of the PDSCH is incorrectly detected due to a PCFICHdetection error is solved, and the transmission efficiency of the systemis improved.

Embodiment 3

A D-PDCCH uses an RB as a basic unit of an aggregation level, andtherefore 14 symbols in a subframe are an RB pair from the perspectiveof the frequency domain. The quantity of time-domain symbols occupied bytwo RBs of two timeslots in an RB pair is 7, but the quantity ofremaining symbols that can transmit the D-PDCCH, after the quantity ofsymbols occupied by a control region is subtracted from the firsttimeslot, is smaller than 7. If the control region occupies 3 symbols,only 4 symbols in the first timeslot may be used to transmit theD-PDCCH. Therefore, compared with 7 symbols in the second timeslot,D-PDCCH information transmitted in each RB is not equalized.

Based on the above technical problem, an embodiment of the presentinvention provides a method for transmitting control information, so asto solve the problem that the quantities of symbols in two timeslots inan RB pair are not equalized and equalize the performance of theD-PDCCH.

A method for transmitting control information specifically includes:

in a subframe, respectively transmitting, by an eNB on two RBs in an RBpair, two D-PDCCHs to one or two UEs, where one D-PDCCH occupies 6symbols in the second timeslot of the subframe, and the other D-PDCCHoccupies 4 symbols or 7-n symbols in the first timeslot of the subframe,where the n is the quantity of symbols occupied by a control region.

An embodiment of the present invention further provides a method forreceiving control information, specifically including:

in a subframe, detecting, by a UE on two RBs in an RB pair, D-PDCCHstransmitted by an eNB, where 6 symbols in the second timeslot of thesubframe are used as a unit to detect a D-PDCCH, and 4 symbols or 7-nsymbols in the first timeslot of the subframe are used as a unit todetect a D-PDCCH, where the n is the quantity of symbols occupied by acontrol region.

With the above transmitting and receiving methods, the problem that thequantities of symbols in two timeslots in an RB pair are not equalizedduring D-PDCCH transmission is solved, and the performance of theD-PDCCH is equalized.

Embodiment 4 Background

In an LTE system of the existing release, a physical downlink controlchannel (PDCCH, Physical Downlink Control Channel) bears controlinformation of uplink and downlink data channels. Specifically, a PDCCHscheduling a downlink data channel is called a downlink scheduling grant(DL_grant, Downlink_grant), and a PDCCH scheduling an uplink datachannel is called an uplink scheduling grant (UL_grant, Uplink_grant).The PDCCH has many downlink control information (DCI, Downlink ControlInformation) formats, for example, DCI formats 0, 1A, 1, 2, 2A, 2C, and4. The PDCCH corresponding to DCI formats 0 and 4 is an uplinkscheduling grant, and the PDCCH corresponding to other several DCIformats is a downlink scheduling grant. Different DCI formats may havedifferent payload sizes (payload sizes). The payload of the PDCCHincludes an information bit, a padding bit, and a cyclic redundancycheck (CRC, Cyclic Redundancy Check) bit, where the information bit is aspecific control information bit field in the DCI, and is specificallyrelated to a carrier bandwidth and a duplex mode. The total quantity ofbits included in the payload is a payload size. Payload sizes ofdifferent DCI formats may also be equal. For example, DCI formats 0 and1A are distinguished by a header bit respectively included in the twoDCI formats. If the quantity of information bits in one DCI format issmaller than that in another DCI format, bits need to be padded in thesmaller DCI format so that payload sizes of the two DCI formats areequal.

In an LTE system of an evolved release, an uplink discontinuoustransmission mechanism is introduced. How to design uplink DCI format 0to support the new feature is a problem to be solved by the presentinvention.

Specific implementation manners of Embodiment 4:

Implementation Manner 1

A method for transmitting control signaling specifically includes:

determining, by a network-side device according to uplink and downlinkbandwidths, a duplex mode of a system, and the quantity of downlinkcarriers configured for a UE, that DCI format 0 of the UE includes aresource allocation type indicator bit; and

transmitting, by the network-side device, a PDCCH corresponding to theDCI format 0 to the user equipment (UE, User Equipment), so that theuser equipment (UE, User Equipment) determines a resource allocationtype of an uplink data channel according to the value of the resourceallocation type indicator bit in the DCI format 0.

The uplink bandwidth is equal to the downlink bandwidth, and the duplexmode of the system is frequency division duplex (FDD, Frequency DivisionDuplexing), and the quantity of downlink carriers configured for the UEis 1. In other words, when the uplink bandwidth is equal to the downlinkbandwidth, and the duplex mode of the system is FDD, if the quantity ofdownlink carriers configured for the UE is greater than 1, the DCIformat 0 of the UE does not include the resource allocation typeindicator bit.

A method for receiving control signaling specifically includes:

determining, by a user equipment (UE, User Equipment) according touplink and downlink bandwidths, a duplex mode of a system, and thequantity of downlink carriers configured for the UE, that DCI format 0of the UE includes a resource allocation type indicator bit; and

detecting, by the UE, a PDCCH corresponding to the DCI format 0, anddetermining a resource allocation type of an uplink data channelaccording to the value of the resource allocation type indicator bit inthe detected DCI format 0.

The uplink bandwidth is equal to the downlink bandwidth, and the duplexmode of the system is frequency division duplex (FDD, Frequency DivisionDuplexing), and the quantity of downlink carriers configured for the UEis 1. In other words, when the uplink bandwidth is equal to the downlinkbandwidth, and the duplex mode of the system is FDD, if the quantity ofdownlink carriers configured for the UE is greater than 1, the DCIformat 0 of the UE does not include the resource allocation typeindicator bit.

A network-side device specifically includes:

a determining module, adapted for the network-side device to determine,according to uplink and downlink bandwidths, a duplex mode of a system,and the quantity of downlink carriers configured for a UE, that DCIformat 0 of the UE includes a resource allocation type indicator bit;and

a transmitting module, adapted for the network-side device to transmit aPDCCH corresponding to the DCI format 0 to the user equipment (UE, UserEquipment).

The uplink bandwidth is equal to the downlink bandwidth, and the duplexmode of the system is frequency division duplex (FDD, Frequency DivisionDuplexing), and the quantity of downlink carriers configured for the UEis 1. In other words, when the uplink bandwidth is equal to the downlinkbandwidth, and the duplex mode of the system is FDD, if the quantity ofdownlink carriers configured for the UE is greater than 1, the DCIformat 0 of the UE does not include the resource allocation typeindicator bit.

A UE specifically includes:

a determining module, adapted for the UE to determine, according touplink and downlink bandwidths, a duplex mode of a system, and thequantity of downlink carriers configured for the UE, that DCI format 0of the UE includes a resource allocation type indicator bit; and

a detecting module, adapted for the UE to detect a PDCCH correspondingto the DCI format 0.

The uplink bandwidth is equal to the downlink bandwidth, and the duplexmode of the system is frequency division duplex (FDD, Frequency DivisionDuplexing), and the quantity of downlink carriers configured for the UEis 1. In other words, when the uplink bandwidth is equal to the downlinkbandwidth, and the duplex mode of the system is FDD, if the quantity ofdownlink carriers configured for the UE is greater than 1, the DCIformat 0 of the UE does not include the resource allocation typeindicator bit.

Specifically, when the uplink bandwidth is equal to the downlinkbandwidth in the FDD system, and the quantity of downlink carriersconfigured for the UE is 1, the quantity of information bits (except theresource allocation type indicator bit) in DCI format 0 is 1 smallerthan the quantity of information bits in DCI format 1A. If the resourceallocation type indicator bit is not considered, a bit needs to bepadded in DCI format 0 so that final payload sizes of the two DCIformats are equal. Therefore, DCI format 0 may include a resourceallocation type indicator bit. In this case, the payload size of DCIformat 0 is the same as that in the above situation where the resourceallocation type indicator bit is not included, which means that theresource allocation type indicator bit occupies the position of thepadding bit. Therefore, the implementation is simple, and theintroduction of the resource allocation type indicator bit does notcause a change to the payload sizes of DCI formats 0 and 1A. Conversely,if the uplink bandwidth is equal to the downlink bandwidth in the FDDsystem, and the quantity of downlink carriers configured for the UE isgreater than 1, an aperiodic channel state information trigger bit isadded to DCI format 0. Therefore, the quantity of information bits inDCI format 0 is equal to the quantity of information bits in DCI format1A. If the resource allocation type indicator bit is added to DCI format0 at this time, bit padding needs to be performed in DCI format 1A.Consequently, the final payload sizes of the two DCI formats change ascompared with those before the resource allocation type indicator bit isadded, and the implementation is complex. Therefore, in this case, DCIformat 0 does not include the resource allocation type indicator bit.

Specifically, for example, assuming that in the FDD system, the uplinkbandwidth and downlink bandwidth are both 20 MHz, if the quantity ofinformation bits in DCI format 0 is 27 and the quantity of informationbits in DCI format 1A is 28 when the quantity of downlink carriersconfigured for the UE is 1, if addition of a resource allocation typeindicator bit is not considered, a bit needs to be padded in DCI format0, so that final payload sizes of the two DCI formats are equal.Therefore, if a resource allocation type indicator bit is added, whichmeans that the position of the padding bit is occupied, final payloadsizes of the two DCI formats do not change as compared with those beforethe resource allocation type indicator bit is added, and theimplementation is simple. If the quantity of downlink carriersconfigured for the UE is greater than 1, the quantity of informationbits in DCI format 0 is 28, which includes 1 more aperiodic channelstate information trigger bit than that in the downlink single carrier,and the quantity of information bits in DCI format 1A is still 28. Ifaddition of a resource allocation type indicator bit is not considered,bit padding is not required for both the two DCI formats, so that thefinal payload sizes of the two DCI formats are equal. In this case, if aresource allocation type indicator bit is added to DCI format 0, thequantity of information bits in DCI format 0 changes to 29, andcorrespondingly, bit padding needs to be performed in DCI format 1A.Consequently, the final payload sizes of the two DCI formats change ascompared with those before the resource allocation type indicator bit isadded, and the implementation is complex. Therefore, in this case, DCIformat 0 does not include the resource allocation type indicator bit.

The above solution ensures that the payload size of DCI format 0 doesnot change after the resource allocation type indicator bit is added toDCI format 0, and it is easy to implement the solution.

Implementation Manner 2

A method for transmitting control signaling specifically includes:

determining, by a network-side device according to uplink and downlinkbandwidths and a duplex mode of a system, information bits except aresource allocation type indicator bit in DCI format 0;

determining, by the network-side device, a set using bit quantities aselements, where the set is {12, 14, 16, 20, 24, 26, 32, 40, 44, 56};

if the total quantity of information bits except the resource allocationtype indicator bit in the DCI format 0 is equal to any bit quantity inthe set, determining, by the network-side device, that the DCI format 0includes the resource allocation type indicator bit; and

transmitting, by the network-side device, a PDCCH corresponding to theDCI format 0 to a user equipment (UE, User Equipment), so that the userequipment (UE, User Equipment) determines a resource allocation type ofan uplink data channel according to the value of the resource allocationtype indicator bit in the DCI format 0.

The above method further includes: when the uplink bandwidth is equal tothe downlink bandwidth, and the duplex mode of the system is FDD, andthe quantity of downlink carriers configured for the UE is greater than1, if the total quantity of information bits except the resourceallocation type indicator bit in the DCI format 0 is equal to any bitquantity in the set, including, by the DCI format 0, the resourceallocation type indicator bit; and if the total quantity of informationbits except the resource allocation type indicator bit in the DCI format0 is not equal to any bit quantity in the set, not including, by the DCIformat 0, the resource allocation type indicator bit.

A method for receiving control signaling specifically includes:

determining, by a UE according to uplink and downlink bandwidths and aduplex mode of a system, information bits except a resource allocationtype indicator bit in DCI format 0;

determining, by the UE, a set using bit quantities as elements, wherethe set is {12, 14, 16, 20, 24, 26, 32, 40, 44, 56};

if the total quantity of information bits except the resource allocationtype indicator bit in the DCI format 0 is equal to any bit quantity inthe set, determining, by the UE, that the DCI format 0 includes theresource allocation type indicator bit; and

detecting, by the UE, a PDCCH corresponding to the DCI format 0, anddetermining a resource allocation type of an uplink data channelaccording to the value of the resource allocation type indicator bit inthe detected DCI format 0.

The above method further includes: when the uplink bandwidth is equal tothe downlink bandwidth, and the duplex mode of the system is FDD, andthe quantity of downlink carriers configured for the UE is greater than1, if the total quantity of information bits except the resourceallocation type indicator bit in the DCI format 0 is equal to any bitquantity in the set, including, by the DCI format 0, the resourceallocation type indicator bit; and if the total quantity of informationbits except the resource allocation type indicator bit in the DCI format0 is not equal to any bit quantity in the set, not including, by the DCIformat 0, the resource allocation type indicator bit.

A network-side device specifically includes:

a first determining module, adapted for the network-side device todetermine, according to uplink and downlink bandwidths and a duplex modeof a system, information bits except a resource allocation typeindicator bit in DCI format 0;

a second determining module, adapted for the network-side device todetermine a set using bit quantities as elements, where the set is {12,14, 16, 20, 24, 26, 32, 40, 44, 56};

a judging module, adapted for the network-side device to determine,according to information indicating that the total quantity ofinformation bits except the resource allocation type indicator bit inthe DCI format 0 is equal to any bit quantity in the set, that the DCIformat 0 includes the resource allocation type indicator bit; and

a transmitting module, adapted for the network-side device to transmit aPDCCH corresponding to the DCI format 0 to a user equipment (UE, UserEquipment).

The above method further includes: when the uplink bandwidth is equal tothe downlink bandwidth, and the duplex mode of the system is FDD, andthe quantity of downlink carriers configured for the UE is greater than1, if the total quantity of information bits except the resourceallocation type indicator bit in the DCI format 0 is equal to any bitquantity in the set, including, by the DCI format 0, the resourceallocation type indicator bit; and if the total quantity of informationbits except the resource allocation type indicator bit in the DCI format0 is not equal to any bit quantity in the set, not including, by the DCIformat 0, the resource allocation type indicator bit.

A UE specifically includes:

a first determining module, adapted for the UE to determine, accordingto uplink and downlink bandwidths and a duplex mode of a system,information bits except a resource allocation type indicator bit in DCIformat 0;

a second determining module, adapted for the UE to determine a set usingbit quantities as elements, where the set is {12, 14, 16, 20, 24, 26,32, 40, 44, 56};

a judging module, adapted for the UE to determine, according toinformation indicating that the total quantity of information bitsexcept the resource allocation type indicator bit in the DCI format 0 isequal to any bit quantity in the set, that the DCI format 0 includes theresource allocation type indicator bit; and

a detecting module, adapted for the UE to detect a PDCCH correspondingto the DCI format 0.

The above method further includes: when the uplink bandwidth is equal tothe downlink bandwidth, and the duplex mode of the system is FDD, andthe quantity of downlink carriers configured for the UE is greater than1, if the total quantity of information bits except the resourceallocation type indicator bit in the DCI format 0 is equal to any bitquantity in the set, including, by the DCI format 0, the resourceallocation type indicator bit; and if the total quantity of informationbits except the resource allocation type indicator bit in the DCI format0 is not equal to any bit quantity in the set, not including, by the DCIformat 0, the resource allocation type indicator bit.

The network-side device may be a base station.

The duplex mode may be frequency division duplex (FDD, FrequencyDivision Duplexing) or time division duplex (TDD, Time DivisionDuplexing), and the duplex mode has an impact on the information bits inthe DCI format. For example, the DCI format in the TDD mode has two moredownlink assignment index (DAI, Downlink Assignment Index) informationbits than that in the FDD mode; or the DCI format of a downlinkscheduling grant in the TDD mode has one more information bit of ahybrid automatic repeat request (HARQ, Hybrid Automatic Repeat Request)process number than that in the FDD mode. The duplex mode of the systemis notified by the base station to the UE through broadcast signaling.

The uplink bandwidth also has an impact on the information bits in theDCI format corresponding to an uplink scheduling grant. Specifically theuplink bandwidth affects the size of the resource allocation bit fieldin the DCI format corresponding to the uplink scheduling grant.Generally, if bandwidth is larger, more bits are allocated forresources. The bandwidth information of the system is notified by thebase station to the UE through broadcast signaling.

Further, configuration information of an aperiodic sounding referencesignal (ASRS, Aperiodic Sounding Reference Signal) signal also affectsinformation bits in DCI formats 0 and 1A. If the ASRS signal isconfigured by radio resource control (RRC, Radio Resource Control)signaling of the base station, an ASRS trigger bit exists in both DCIformats 0 and 1A; if the ASRS signal is not configured, the bit does notexist in the two DCI formats.

Further, in the case of carrier aggregation (CA, Carrier Aggregation),that is, in a case where the base station may configure multiplecarriers for a UE, the quantity of downlink carriers configured by RRCsignaling for the UE also affects information bits in DCI format 0.Specifically, if the UE is not configured with downlink CA, that is,only one downlink carrier exists, the quantity of aperiodic channelstate information trigger bits in DCI format 0 is 1; and if the UE isconfigured with downlink CA, that is, at least two downlink carriersexist, the quantity of aperiodic channel state information trigger bitsin DCI format 0 is 2.

Sizes of other bit fields in DCI format 0 do not depend on the uplinkbandwidth and duplex mode and even further the configuration informationof the aperiodic sounding signal and the quantity of downlink carriersconfigured for the UE. Therefore, the base station and the UE candetermine all information bits except the resource allocation typeindicator bit in DCI format 0 according to the uplink bandwidth andduplex mode of the current system and even configuration information ofthe aperiodic sounding signal and the quantity of downlink carriersconfigured for the UE.

With respect to existence or nonexistence of the resource allocationtype indicator bit, because the payload size of DCI format 0 is notexpected to change due to introduction of the information bit, it may beconsidered that the resource allocation type indicator bit is added whena padding bit exists in DCI format 0. For example, when the quantity ofinformation bits in DCI format 0 is smaller than the quantity ofinformation bits in DCI format 1A, a bit needs to be padded in the DCIformat 0 so that final payload sizes of the two DCI formats are equal.In this case, the resource allocation type indicator bit may be added toDCI format 0, and the final payload size of DCI format 0 does notchange.

Next, the base station and UE determine a set {12, 14, 16, 20, 24, 26,32, 40, 44, 56} using bit quantities as elements. Then, if the totalquantity of information bits except the resource allocation typeindicator bit in the DCI format 0 is equal to any bit quantity in theset, the base station and UE determine that the DCI format 0 includes aresource allocation type indicator bit. The above judging condition mayfurther include three cases. The first case is that when the totalquantity of information bits except the resource allocation typeindicator bit in the DCI format 0 is smaller than the total quantity ofinformation bits in DCI format 1A, to make the final payload sizes ofDCI formats 0 and 1A equal, padding is required in DCI format 0, andtherefore, in this case, a resource allocation type indicator bit may beadded. The second case is that when the total quantity of informationbits except the resource allocation type indicator bit in the DCI format0 is equal to the total quantity of information bits in DCI format 1A,generally, bit padding is not required in both the DCI formats, but ifthe total quantity of information bits is any bit quantity in the set atthis time, a bit needs to be padded in DCI format 1A of thecorresponding downlink scheduling grant to avoid the bit quantities inthe set, because if avoidance is not performed, DCI format 1A may bedetected correctly by using different aggregation levels. For example,the eNB uses aggregation level 2 to schedule a downlink scheduling grantcorresponding to DCI format 1A for the UE. The UE may correctly detectDCI format 1 by using aggregation level 1. As a result, a channelcollision of uplink HARQ acknowledgement information corresponding tothe downlink data packet may occur. In a case where the quantity ofinformation bits in the DCI format of the uplink scheduling grant is anybit quantity in the set, avoidance is not required, because the channelof downlink HARQ acknowledgement information corresponding to uplinkdata scheduling has no relationship with the aggregation level. Next, abit needs to be padded in DCI format 0 again so that the final payloadsizes of the two DCI formats are equal. The third case is that when thetotal quantity of information bits except the resource allocation typeindicator bit in the DCI format 0 is greater than the total quantity ofinformation bits in DCI format 1A, to make the final payload sizes ofDCI formats 0 and 1A equal, bit padding is required in DCI format 1A sothat the quantity of information bits in DCI format 1A is equal to thatin DCI format 0. In this case, because the quantity of information bitsafter padding is a bit quantity in the set again, to avoid this bitquantity, another bit is padded in DCI format 1A. Then, further a bitneeds to be padded in DCI format 0 to make the final payload sizes ofthe two DCI formats equal. For the first and second cases, padding bitsfinally exist in DCI format 0. Therefore, addition of the resourceallocation type indicator bit may be supported.

For the second and third cases, the following examples are used fordescription:

Example 1

For the FDD system, both uplink bandwidth and downlink bandwidths are 5MHz. If no ASRS trigger bit is configured, and the downlink adopts CA,both quantities of information bits in DCI formats 0 and 1A are 24, andjust fall within the above set. Therefore, a bit is padded in DCI format1A, and correspondingly, a resource allocation type indicator bit may beadded to DCI format 0.

Example 2

For the FDD system, uplink bandwidth is 15 MHz and downlink bandwidth is10 MHz. If no ASRS trigger bit is configured, and the downlink isconfigured with only a single carrier, both quantities of informationbits in DCI formats 0 and 1A are 26, and just fall within the above set.Therefore, a bit is padded in DCI format 1A, and correspondingly, aresource allocation type indicator bit may be added to DCI format 0.

Example 3

For the TDD system, uplink bandwidth is 5 MHz, and downlink bandwidth is3 MHz. If no ASRS trigger bit is configured, and the downlink adopts CA,the quantity of information bits in DCI format 0 is 26, and the quantityof information bits in DCI format 1A is 25. Because the quantity ofinformation bits in DCI format 1A is smaller than that in DCI format 0at this time, a bit needs to be padded in DCI format 1A to change thequantity to 26, but the quantity of information bits in DCI format 1Aafter padding falls within the above set again. Therefore, a bit ispadded again in DCI format 1A to change the quantity to 27, but thequantity of information bits in DCI format 0 is 26, and therefore aresource allocation type indicator bit may be added to DCI format 0.

Finally, the base station or UE performs scheduling or is scheduledthrough the PDCCH corresponding to the DCI format 0. The base stationand UE interpret the corresponding resource allocation type indicatorbit and process the uplink data channel.

The above solution ensures that the payload size of DCI format 0 doesnot change after the resource allocation type indicator bit is added toDCI format 0, and it is easy to implement the solution.

It should be noted that the relational terms herein such as first andsecond are used only to differentiate an entity or operation fromanother entity or operation, and do not require or imply any actualrelationship or sequence between these entities or operations. Moreover,the terms “include”, “comprise”, and any variation thereof are intendedto cover a non-exclusive inclusion. Therefore, a process, method,article, or device that includes a series of elements not only includessuch elements, but also includes other elements not specified expressly,or may include inherent elements of the process, method, article, ordevice. If no more limitations are made, an element limited by“including one . . . ” does not exclude other same elements existing inthe process, method, article, or device that includes the element.

A person of ordinary skill in the art may understand that all or a partof the steps of the foregoing method embodiments may be implemented by aprogram instructing relevant hardware. The program may be stored in acomputer readable storage medium. The storage medium may include aROM/RAM, a magnetic disk, and an optical disk.

The foregoing descriptions are merely exemplary embodiments of thepresent invention, but are not intended to limit the protection scope ofthe present invention. Any modifications, equivalent replacements, orimprovements made within the spirit and principle of the presentinvention should fall within the protection scope of the presentinvention.

What is claimed is:
 1. A method for detecting information, comprising:determining, by a user equipment (UE), a search space of a D-physicaldownlink control channel (D-PDCCH), wherein the search space comprisesat least one D-PDCCH candidate detection position at a specificaggregation level; obtaining, by the UE, a mapping relationship betweenantenna port information of at least one antenna port occupied by theD-PDCCH and second information, wherein the second informationcomprises: an aggregation level of the D-PDCCH; or resources occupied bythe D-PDCCH; or a combination of an aggregation level of the D-PDCCH andresources occupied by the D-PDCCH; and detecting, by the UE, the D-PDCCHin the search space according to the obtained mapping relationship. 2.The method according to claim 1, wherein the mapping relationshipbetween the antenna port information and resources occupied by theD-PDCCH comprises any one or any combination of the following mappingrelationships: a mapping relationship between the antenna portinformation and time-domain resources where the D-PDCCH is located; amapping relationship between the antenna port information and a resourceblock (RB) where the D-PDCCH is occupied; a mapping relationship betweenthe antenna port information and a control channel element (CCE) wherethe D-PDCCH is occupied; or a mapping relationship between the antennaport information and a candidate detection position at a specificaggregation level.
 3. The method according to claim 1, wherein: theantenna port information comprises one type, and the obtained mappingrelationship is a one-to-one or one-to-many mapping relationship; or theantenna port information comprises at least two types, and the obtainedmapping relationship is a many-to-one or many-to-many mappingrelationship.
 4. The method according to claim 1, wherein the antennaport information is obtained through broadcast signaling, radio resourcecontrol (RRC) dedicated signaling, or media access control (MAC) layersignaling, or physical layer signaling.
 5. A method for transmittinginformation, wherein the method is applicable to a base station andcomprises: determining, by a base station, a search space of aD-physical downlink control channel (D-PDCCH), wherein the search spacecomprises at least one D-PDCCH candidate detection position at aspecific aggregation level; and obtaining, by the base station, amapping relationship between antenna port information of at least oneantenna port occupied by the D-PDCCH and second information, wherein thesecond information comprises: an aggregation level of the D-PDCCH; orresources occupied by the D-PDCCH; or a combination of an aggregationlevel of the D-PDCCH and resources occupied by the D-PDCCH; andtransmitting, by the base station, the D-PDCCH in the search space to auser equipment (UE) according to the obtained mapping relationship. 6.The method according to claim 5, wherein the mapping relationshipbetween the antenna port information and resources occupied by theD-PDCCH comprises any one or any combination of the following mappingrelationships: a mapping relationship between the antenna portinformation and time-domain resources where the D-PDCCH is located; amapping relationship between the antenna port information and a resourceblock (RB) where the D-PDCCH is occupied; a mapping relationship betweenthe antenna port information and a control channel element (CCE) wherethe D-PDCCH is occupied; or a mapping relationship between the antennaport information and a candidate detection position at a specificaggregation level.
 7. The method according to claim 5, wherein: theantenna port information comprises one type, and the obtained mappingrelationship is a one-to-one or one-to-many mapping relationship; or theantenna port information comprises at least two types, and the obtainedmapping relationship is a many-to-one or many-to-many mappingrelationship.
 8. A user equipment (UE), comprising: a memory storagecomprising a program; one or more processors in communication with thememory storage, wherein the one or more processors execute the programto: determine a search space of a D-physical downlink control channel(D-PDCCH), wherein the search space comprises at least one D-PDCCHcandidate detection position at a specific aggregation level; obtain amapping relationship between antenna port information of at least oneantenna port occupied by the D-PDCCH and second information, wherein thesecond information comprises: an aggregation level of the D-PDCCH; orresources occupied by the D-PDCCH; or a combination of an aggregationlevel of the D-PDCCH and resources occupied by the D-PDCCH; and areceiver in communication with the processor and adapted to detect theD-PDCCH in the search space according to the obtained mappingrelationship.
 9. The user equipment according to claim 8, wherein themapping relationship between the antenna port information and resourcesoccupied by the D-PDCCH comprises any one or any combination of thefollowing mapping relationships: a mapping relationship between theantenna port information and time-domain resources where the D-PDCCH islocated; a mapping relationship between the antenna port information anda resource block (RB) where the D-PDCCH is occupied; a mappingrelationship between the antenna port information and a control channelelement (CCE) where the D-PDCCH is occupied; or a mapping relationshipbetween the antenna port information and a candidate detection positionat a specific aggregation level.
 10. The user equipment according toclaim 8, wherein: the antenna port information comprises one type, andthe obtained mapping relationship is a one-to-one or one-to-many mappingrelationship; or the antenna port information comprises at least twotypes, and the obtained mapping relationship is a many-to-one ormany-to-many mapping relationship.
 11. A base station, comprising: atransmitter; a memory storage comprising a program; one or moreprocessors in communication with the transmitter and the memory storage,wherein the one or more processors execute the program to: determine asearch space of a D-physical downlink control channel (D-PDCCH), whereinthe search space comprises at least one D-PDCCH candidate detectionposition at a specific aggregation level; and a receiver, incommunication with the processor and adapted to obtain a mappingrelationship between antenna port information of at least one antennaport occupied by the D-PDCCH and second information, wherein the secondinformation comprises: an aggregation level of the D-PDCCH; or resourcesoccupied by the D-PDCCH; or a combination of an aggregation level of theD-PDCCH and resources occupied by the D-PDCCH; and wherein thetransmitter is adapted to transmit the D-PDCCH in the search space to auser equipment (UE) according to the obtained mapping relationship. 12.The base station according to claim 11, wherein the mapping relationshipbetween the antenna port information and resources occupied by theD-PDCCH comprises any one or any combination of the following mappingrelationships: a mapping relationship between the antenna portinformation and time-domain resources where the D-PDCCH is located; amapping relationship between the antenna port information and a resourceblock (RB) where the D-PDCCH is occupied; a mapping relationship betweenthe antenna port information and a control channel element (CCE) wherethe D-PDCCH is occupied; or a mapping relationship between the antennaport information and a candidate detection position at a specificaggregation level.
 13. The base station according to claim 11, wherein:the antenna port information comprises one type, and the mappingrelationship obtained by the receiver is a one-to-one or one-to-manymapping relationship; or the antenna port information comprises at leasttwo types, and the mapping relationship obtained by the receiver is amany-to-one or many-to-many mapping relationship.